Conventional mounting of a thin flexible display object such as a painting or drawing or large sheet has been accomplished heretofore interposing such display object between a pair of sheets, one of which is transparent, and in some manner securing the sheets together.
Unless the display object is adhered or otherwise affixed to one or both of the covering sheets, it will lie loose between the sheets, and curvatures in the outer surfaces of the display object will be apparent.
It is known to adhere a sheet to a backing with a layer of adhesive by temporarily positioning the sheet and backing within a vacuum chamber temporarily removing the air therefrom and applying heat for bonding the sheet to the backing after which the sheet and backing have been removed from such chamber. Such a method of securing a flexible sheet to a stiff backing is shown in U.S. Pat. No. 2,620,289.
It is known to hermetically seal a pair of glass plates together by providing a sealant material peripherally around a pair of opposed spaced glass plates to provide a hermetically sealed storage chamber. An illustration of this is shown in U.S. Pat. No. 3,733,237.
It is known in the photographic industry to provide over a glass frame a flexible rubber blanket peripherally secured thereto wherein a negative and a sensitized sheet be interposed in contact relationship by evacuating the space between said glass and blanket for a momentary photographic exposure after which the vacuum is eliminated and the exposed sheet removed. Examples of this are found in U.S. Pat. Nos. 3,738,890 and 3,951,724. Such apparatus is employed for photographic contact printing.